Marga Hoogendoorn

121 Strengths and limitations A strength of this study is the large amount of Nursing Activities Score from patients in both the COVID-period and the non-COVID period. The number of participating hospitals was limited, but we included data of all shifts and patients in both periods. The included ICUs were representative of Dutch ICUs regarding hospital type (teaching and non- teaching hospitals) and geographical location. The included patients were representative compared to the patients of all the other ICUs in the NICE-database, except for the APS- score and the higher mortality in COVID-patients. The mortality in our study group was however comparable with the mortality in anotherCOVID-19 study about COVID in the Netherlands 1 . Another strength is that we were able to analyze the raw which enabled insight in which aspects the Nursing Activities Score differed between the groups. Within this researchwe did not analyze every aspect of the nursingworkload. As COVID-19 is a new disease it is possible that the workload in the beginning of the pandemic period was higher due to the unfamiliarity with these kinds of patients. It is possible that this unfamiliarity and lack of knowledge about the clinical course of COVID-19 had an impact on interventions such as being bedside. Analysis of the workload in next COVID-19 waves can help us in this respect. Another limitation is that we do not have data on non-ICU (general or anesthesia) nursing staff in our capacity module. The NAS was scored by the ICU nurse, but the support of a non-ICU nurse can influence (lower) the time needed for the nursing interventions. We do not know the exact impact of the support by other staff on the workload of the ICU nurses. But, however helpful the support of non-ICU nurses in daily care has been, this support also added a dimension of coordination and supervision to the role of the ICU nurse Unfortunately we were not able to analyze the impact of this change of the nursing role of the ICU nurse on the nursing workload. However, we have learned from this period that participation of other nurses in the daily care on an ICU is possible. They can support the ICU nurse in e.g., mobilization of the patient, hygienic procedures or assistance in patient and family care. Further research should focus on opportunities and restrictions on the changing and coordinating role of the ICU nurse. CONCLUS I ONS This study showed a higher nursing workload during the COVID-19 period, expressed in both a higher number of patients per nurse and a higher nursing workload per nurse. The higher workload per nurse can be explained by the higher workload of COVID-19 patients compared to pneumonia patients, an increase of the proportion of COVID-19